A Simple Model for On-Sensor Phase-Detection Autofocusing Algorithm

Przemysław Śliwiński, Paweł Wachel

Institute of Computer Engineering, Control and Robotics, Wroc?aw University of Technology, Wroc?aw, Poland.

DOI: 10.4236/jcc.2013.16003                

Abstract

A simple model of the phase-detection autofocus device based on the partially masked sensor pixels is described. The cross-correlation function of the half-images registered by the masked pixels is proposed as a focus function. It is shown that—in such setting—focusing is equivalent to searching of the cross-correlation function maximum. Application of stochastic approximation algorithms to unimodal and non-unimodal focus functions is shortly discussed.

Keywords

Phase Detection Autofocus; On-Sensor Circuit; Formal Model; Cross-Correlation; Stochastic Approximation

Conflicts of Interest

The authors declare no conflicts of interest.

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